Paper towel dispensers contain a roll of paper towelling which is fed from the dispenser through a discharge opening by operation of a pair of cooperating feed rolls. In the conventional dispenser, the feed rolls are operated by manual movement of a crank or lever on the side of the dispenser.
Recently dispensers have incorporated a provision for automatically transferring feed from a partially consumed roll to a fresh or reserve roll. In dispensers of this type, as shown in U.S. Pat. Nos. 4,106,684, 4,165,138 and 3,628,743, the partially consumed roll is mounted in a cradle in the lower portion of the dispenser and the sheet is fed through cooperating feed rolls to the discharge opening. A fresh or reserve roll is mounted in a cradle above the partially consumed roll, and the free end of the sheet of the fresh roll is normally draped above the feed rolls. In dispensers of this type, a transfer mechanism is utilized which will automatically transfer feed to the reserve roll when the partially consumed roll is fully depleted. In some cases the transfer mechanism senses the diameter of the partially consumed roll and will transfer the feed when the diameter has been reduced to a predetermined value. In other transfer mechanisms, such as shown in U.S. Pat. No. 4,165,138, a sensing finger rides on the sheet being dispensed from the partially consumed roll and senses the end of the sheet. When the end of the sheet is drawn beyond the sensing finger, the finger will drop into a groove in one of the feed rolls to actuate a transfer finger which moves the free end of the sheet of the reserve roll into the nip between the feed rolls, so that the reserve roll is then fed by the feed rolls.